Display device and manufacturing method thereof

ABSTRACT

A display device includes: a substrate; an inorganic insulating layer disposed on the substrate; a conductor disposed on the inorganic insulating layer; and an organic insulating layer disposed on the conductor, where an opening is defined through the organic insulating layer to expose a part of the upper surface of the conductor, and at least one material selected from a siloxane, a thiol, a phosphate, a disulfide including a sulfur series, and an amine is bonded on the part of the upper surface of the conductor exposed through the opening.

This application claims priority to Korean Patent Application No.10-2020-0031526, filed on Mar. 13, 2020, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the content of which in its entirety isherein incorporated by reference.

BACKGROUND (a) Field

The disclosure relates to a display device and a manufacturing methodthereof.

(b) Description of the Related Art

A display device as device for displaying an image may include a liquidcrystal display, an organic light emitting diode display, and the like.

The organic light emitting diode display typically includes a pluralityof transistors disposed on a substrate, a driving element including aplurality of conductors, and an organic light emitting element. Theorganic light emitting element may include two electrodes facing eachother and an organic emission layer interposed therebetween. Electronsand holes provided from the two electrodes recombine in the organicemission layer to generate excitons, and the generated excitons changefrom an excited state to a ground state and then light may be emitted.

SUMMARY

In an organic light emitting diode display, a surface of an organicinsulating layer covering a driving element may be planarized to easilycontrol the thickness of a pixel electrode and an emission layer toimprove luminance uniformity of the light emitted from the organic lightemitting element.

In such an organic light emitting diode display, a chemical mechanicalpolishing method, in which mechanical polishing and chemical polishingare performed together, may be used to planarize the surface of theorganic insulating layer. A device that performs a chemical mechanicalpolishing may include a polishing pad, a chuck that fixes and rotates asubstrate as a polishing target to be polished, and a slurry dispenserthat supplies a slurry as basic constituent elements. In some cases, thesubstrate is fixed, and the polishing pad is rotated to perform theplanarization process.

Embodiments of the invention relate to a display device in which aslurry, by-products, and the like is effectively prevented fromremaining in a conductor of a driving element after a polishing processof an organic insulating layer is performed.

An embodiment of a display device according to the invention includes: asubstrate; an inorganic insulating layer disposed on the substrate; aconductor disposed on the inorganic insulating layer; and an organicinsulating layer disposed on the conductor, where an opening is definedthrough the organic insulating layer to expose a part of the uppersurface of the conductor, and at least one material selected from asiloxane, a thiol, a phosphate, a disulfide including a sulfur series,and an amine is bonded on the part of the upper surface of the conductorexposed through the opening.

In an embodiment, the conductor may include at least one materialselected from titanium (Ti), iron (Fe), nickel (Ni), copper (Cu),molybdenum (Mo), indium tin oxide (“ITO”), and indium zinc oxide(“IZO”).

In an embodiment, the substrate may include a display area and anon-display area surrounding the display area, and the conductor mayinclude a first conductor disposed in the display area and a secondconductor disposed in the non-display area.

In an embodiment, the display device may further include a pixelelectrode disposed on the organic insulating layer in the display are,an emission layer disposed on the pixel electrode in the display are,and a common electrode disposed on the emission layer in the displayare, where the at least one material selected from the siloxane, thethiol, the phosphate, the disulfide including the sulfur series, and theamine may be disposed between the pixel electrode and the firstconductor.

In an embodiment, the display device may further include a semiconductorlayer disposed on the substrate in the display area, a gate insulatinglayer disposed on the semiconductor layer in the display area, a gateconductor disposed on the semiconductor layer in the display area, and adata conductor disposed on the gate conductor in the display area, wherethe data conductor may be defined by the first conductor, and theinorganic insulating layer may be disposed between the gate conductorand the data conductor.

In an embodiment, the first conductor may be electrically connected tothe pixel electrode through the opening of the organic insulating layer.

In an embodiment, the gate conductor may include a gate electrode, thedata conductor may include a drain electrode and a source electrode, andthe gate electrode, the drain electrode, the source electrode and thesemiconductor layer may collectively define a transistor.

An embodiment of a manufacturing method of a display device according tothe invention includes: providing a conductor on a substrate; providingan organic insulating layer on the conductor and forming an openingthrough the organic insulating layer to expose a part of an uppersurface of the conductor; depositing a sacrificial layer to cover asurface of the organic insulating layer and the part of the uppersurface of the conductor exposed through the opening; polishing an uppersurface of the organic insulating layer; and surface-treating thesacrificial layer on a side surface of the organic insulating layer andthe upper surface of the conductor, where the sacrificial layer includesa self-assembled monolayer.

In an embodiment, the self-assembled monolayer may include a head group,a hydrocarbon chain and a terminal functional group, and the head groupmay include at least one selected from a siloxane, a thiol, and aphosphate. In an embodiment, the terminal functional group may includeat least one selected from a trifluoromethyl (—CF₃), a difluorocarbene(—CF₂), a methyl (—CH₃), a methylene (—CH₂), a fluoro (—F), a hydroxylgroup (—OH), carbon (—C), and silicon (—Si).

In an embodiment, the sacrificial layer may be deposited by a thermalevaporation, a liquid coating, a chemical vapor deposition, a physicalvapor deposition, or a sputtering.

In an embodiment, the upper surface of the organic insulating layercovered by the sacrificial layer may include protrusions anddepressions.

In an embodiment, the head group may be disposed on the upper surface ofthe conductor on which a surface treatment is completed.

In an embodiment, the conductor may include at least one materialselected from titanium (Ti), iron (Fe), nickel (Ni), copper (Cu),molybdenum (Mo), ITO, and IZO.

In an embodiment, the organic insulating layer may include at least oneorganic material selected from acryl resin, epoxy resin, phenolic resin,polyamide resin, and polyimide resin.

In an embodiment, the polishing the upper surface of the organicinsulating layer may include using a chemical mechanical polishingmethod.

In an embodiment, the chemical mechanical polishing method may beperformed by contacting a polishing pad to the upper surface of theorganic insulating layer and supplying a slurry.

In an embodiment, the substrate may include a display area and anon-display area surrounding the display area, and the conductor mayinclude a first conductor provided in the display area and a secondconductor provided in the non-display area.

In an embodiment, the polishing pad may overlap the display area and thenon-display area when the polishing pad contacts the upper surface ofthe organic insulating layer for the chemical mechanical polishingmethod.

In an embodiment, the manufacturing method may further include providinga pixel electrode, an emission layer, and a common electrode on theorganic insulating layer in the display area, where the self-assembledmonolayer may include a head group, a hydrocarbon chain, and a terminalfunctional group, the head group may include at least one selected froma siloxane, a thiol, and a phosphate, and the head group may be disposedbetween the pixel electrode and the first conductor.

According to embodiments, the sacrificial layer is provided on thesurface of the organic insulating layer and the sacrificial layer iscleaned after the organic insulating layer polishing process, therebyproviding the display device in which a slurry, polishing by-products,etc. are effectively prevented from remaining in the conductor.

In such embodiments, by forming the sacrificial layer on the surface ofthe conductor and performing the organic insulating layer polishingprocess, the conductor may be protected by not directly exposing thesurface of the conductor to the polishing pad.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects and features of the invention will becomemore apparent by describing in detail embodiments thereof with referenceto the attached drawings, in which:

FIG. 1 is a schematic top plan view of a display device according to anembodiment;

FIG. 2 is a cross-sectional view partially showing a display area and anon-display area of a display device according to an embodiment;

FIG. 3 is a structural view of a material forming a sacrificial layer ofa display device according to an embodiment;

FIG. 4 to FIG. 8 are views showing a manufacturing method of a displaydevice according to an embodiment; and

FIG. 9 is a schematic cross-sectional view of a display device accordingto an embodiment.

DETAILED DESCRIPTION

The invention will be described more fully hereinafter with reference tothe accompanying drawings, in which embodiments of the invention areshown. This invention may, however, be embodied in different forms andshould not be construed as limited to the embodiments set forth herein.Rather, these embodiments are provided so that this disclosure will bethorough and complete, and will filly convey the scope of the inventionto those skilled in the art. The same reference numbers indicate thesame components throughout the specification

In the drawings, the sizes and thicknesses of the components are merelyshown for convenience of explanation, and therefore the invention is notnecessarily limited to the illustrations described and shown herein. Inthe drawings, the thickness of layers, films, panels, regions, etc., areexaggerated for clarity. In the drawings, for better understanding andease of description, the thickness of some layers and areas isexaggerated.

It will be understood that when an element such as a layer, film,region, or substrate is referred to as being “on” another element, itcan be directly on the other element or intervening elements may also bepresent. In contrast, when an element is referred to as being “directlyon” another element, there are no intervening elements present. Further,in the specification, the word “on” or “above” means positioned on orbelow the object portion, and does not necessarily mean positioned onthe upper side of the object portion based on a gravitational direction.

It will be understood that, although the terms “first,” “second,”“third” etc. may be used herein to describe various elements,components, regions, layers and/or sections, these elements, components,regions, layers and/or sections should not be limited by these terms.These terms are only used to distinguish one element, component, region,layer or section from another element, component, region, layer orsection. Thus, “a first element,” “component,” “region,” “layer” or“section” discussed below could be termed a second element, component,region, layer or section without departing from the teachings herein.The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting. As used herein,“a”, “an,” “the,” and “at least one” do not denote a limitation ofquantity, and are intended to include both the singular and plural,unless the context clearly indicates otherwise. For example, “anelement” has the same meaning as “at least one element,” unless thecontext clearly indicates otherwise. “At least one” is not to beconstrued as limiting “a” or “an.” “Or” means “and/or.” As used herein,the term “and/or” includes any and all combinations of one or more ofthe associated listed items. It will be further understood that theterms “comprises” and/or “comprising,” or “includes” and/or “including”when used in this specification, specify the presence of statedfeatures, regions, integers, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, regions, integers, steps, operations, elements,components, and/or groups thereof.

Furthermore, relative terms, such as “lower” or “bottom” and “upper” or“top,” may be used herein to describe one element's relationship toanother element as illustrated in the Figures. It will be understoodthat relative terms are intended to encompass different orientations ofthe device in addition to the orientation depicted in the Figures. Forexample, if the device in one of the figures is turned over, elementsdescribed as being on the “lower” side of other elements would then beoriented on “upper” sides of the other elements. The term “lower,” cantherefore, encompasses both an orientation of “lower” and “upper,”depending on the particular orientation of the figure. Similarly, if thedevice in one of the figures is turned over, elements described as“below” or “beneath” other elements would then be oriented “above” theother elements. The terms “below” or “beneath” can, therefore, encompassboth an orientation of above and below.

Further, herein, the phrase “in a plan view” means when an objectportion is viewed from above, and the phrase “in a cross-section” meanswhen a cross-section taken by vertically cutting an object portion isviewed from the side.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this disclosure belongs. It willbe further understood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning that isconsistent with their meaning in the context of the relevant art and thepresent disclosure, and will not be interpreted in an idealized oroverly formal sense unless expressly so defined herein.

Embodiments are described herein with reference to cross sectionillustrations that are schematic illustrations of idealized embodiments.As such, variations from the shapes of the illustrations as a result,for example, of manufacturing techniques and/or tolerances, are to beexpected. Thus, embodiments described herein should not be construed aslimited to the particular shapes of regions as illustrated herein butare to include deviations in shapes that result, for example, frommanufacturing. For example, a region illustrated or described as flatmay, typically, have rough and/or nonlinear features. Moreover, sharpangles that are illustrated may be rounded. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the precise shape of a region and are notintended to limit the scope of the present claims.

Hereinafter, embodiments of the invention will be described in detailwith reference to the accompanying drawings.

Hereinafter, a display device according to an embodiment is describedwith reference to FIG. 1 to FIG. 3.

FIG. 1 is a schematic top plan view of a display device according to anembodiment, and FIG. 2 is a cross-sectional view partially showing adisplay area and a non-display area of a display device according to anembodiment. FIG. 3 is a structural view of a material forming asacrificial layer of a display device according to an embodiment.

Referring to FIG. 1, an embodiment of a display device includes adisplay area DA and a non-display area NA.

The display area DA is an area in which an image is displayed by aplurality of pixels PX included therein, and the non-display area NA isan area in which the image is not displayed. The non-display area NA maybe the area surrounding the display area DA. A plurality of pads PAD maybe disposed in the non-display area NA. The pad PAD may be electricallyconnected to an external driving circuit element, a flexible printedcircuit board (“PCB”), or a chip-on-film (“COF”). According to anembodiment, the non-display area NA in which the pad PAD is disposed maybe bent.

In an embodiment, the display device may be an organic light emittingdiode display including an organic light emitting element disposed ineach pixel PX, but not being limited thereto. In an alternativeembodiment, the display device may be a liquid crystal display.

Referring to FIG. 2, an embodiment of a display device includes asubstrate 100 and a display element 200 disposed on the substrate 100.The display element 200 includes an inorganic insulating layer 160,conductors 175 and 177, a driving element including an organicinsulating layer 180, and a light-emitting element LED.

The substrate 100 may be a flexible substrate 100 including or made ofglass or a polymer such as polyimide (“PI”), polyamide (“PA”), andpolyethylene terephthalate (“PET”).

The inorganic insulating layer 160 and the first conductor 175 aredisposed in the display area DA on the substrate 100, and the secondconductor 177 is disposed in the non-display area NA on the substrate100. The second conductor 177 may correspond to the pad PAD of FIG. 1,and may correspond to wiring disposed in the non-display area NA. Thefirst conductor 175 and the second conductor 177 may be referred to asthe conductors 175 and 177. A buffer layer (120 of FIG. 9) and a gateinsulating layer (140 of FIG. 9) may be disposed in an element part 20disposed between the substrate 100 and the inorganic insulating layer160, a semiconductor layer (130 of FIG. 9) may be disposed between thesubstrate 100 and the buffer layer 120, and gate conductors 175 and 177may be further disposed on the gate insulating layer 140. The inorganicinsulating layer 160 may be disposed on the gate conductors 175 and 177.The configuration that may be disposed between the substrate 100 and theinorganic insulating layer 160 will be described later in greater detailwith reference to FIG. 9.

The first conductor 175 and the second conductor 177 may have a singlelayer structure or a multi-layer structure, each layer including atleast one metal selected from titanium (Ti), gold (Au), copper (Cu),nickel (Ni), silver (Ag), aluminum (Al), molybdenum (Mo), chromium (Cr),and tantalum (Ta), or their alloys. In one embodiment, for example,where the first conductor 175 and the second conductor 177 have a triplelayer structure with an upper layer, an intermediate layer, and a lowerlayer, the upper layer may include at least one selected from titanium(Ti), iron (Fe), nickel (Ni), copper (Cu), molybdenum (Mo), indium tinoxide (“ITO”), and indium zinc oxide (“IZO”).

In an embodiment, the organic insulating layer 180 may be disposed onthe first conductor 175 and the inorganic insulating layer 160 in thedisplay area DA. The organic insulating layer 180 for planarizing thesurface of the substrate 100 including the display element may includeat least one material selected from an acryl resin, an epoxy resin, aphenolic resin, a polyamide resin, and a polyimide resin. In anembodiment, the organic insulating layer 180 may be disposed in thenon-display area NA to partially overlap the second conductor 177. Theorganic insulating layer 180 may planarize the upper portion of the padPAD, the wiring, and the like to compensate for the step difference dueto the pad PAD, the wiring, the driving unit, and the like.

In an embodiment, an opening 61 for exposing a part of the upper surfaceof the first conductor 175 may be defined or formed through the organicinsulating layer 180. In such an embodiment, an opening 62 for exposinga part of the upper surface of the second conductor 177 may be definedor formed through the organic insulating layer 180. In an embodiment, atleast one material selected from a siloxane, a thiol, a phosphate, adisulfide including sulfur series, and an amine may be disposed on theconductors 175 and 177 exposed by the openings 61 and 62 of the organicinsulating layer 180. At least one material selected from a siloxane, athiol, a phosphate, a disulfide including a sulfur series, and an amine,as a material configuring a head group 310 of a sacrificial layer 300,which will be described later in greater detail, may not be completelyremoved by a cleaning process of the sacrificial layer 300, but maypartially remain on the conductors 175 and 177. In such an embodiment,where the at least one material selected from a siloxane, a thiol, aphosphate, a disulfide including a sulfur series, and an amine remainsabove the conductors 175 and 177, electrical performance of theconductors 175 and 177 may not affected thereby.

A pixel electrode 191 is disposed on the organic insulating layer 180.In the display area DA, the pixel electrode 191 may be electricallyconnected to the first conductor 175 through the opening 61 of theorganic insulating layer 180. The first conductor 175 may be a drainelectrode of a transistor. The at least one material selected from asiloxane, a thiol, a phosphate, a disulfide including a sulfur series,and an amine may be disposed between the pixel electrode 191 and thefirst conductor 175. However, such materials do not affect theelectrical connection between the pixel electrode 191 and the firstconductor 175.

A partition 360 is disposed on the pixel electrode 191 and the organicinsulating layer 180, and an opening 361 for exposing a part of thepixel electrode 191 is defined or formed through the partition 360. Anemission layer 370 is disposed in the opening 361 of the partition 360,and a common electrode 270 is disposed on the emission layer 370. Thepixel electrode 191, the emission layer 370, and the common electrode270 may constitute or collectively define the light-emitting elementLED.

The material remaining on the upper surfaces of the conductors 175 and177 of FIG. 2 correspond to a material forming the sacrificial layer 300described later. In an embodiment, the sacrificial layer 300 is aself-assembled monolayer. Here, the self-assembled monolayer refers to aregularly ordered organic molecular film spontaneously coated on thesurface of a given substrate. The self-assembled monolayer may includean organic silicon, or thiol-based, amine-based, or silane-based organicmaterials. In one embodiment, for example,trichloro[1H,1H,2H,2H-perfluorooctyl] silane (CF₃CF₂₅CH₂CH₂SiCl₃) ordodecanethiol (CH₃(CH₂)₁₁SH) may be used as the self-assembledmonolayer.

Referring to FIG. 3, the self-assembled monolayer includes the headgroup 310, a hydrocarbon chain 311, and a terminal functional group 312.

The head group 310 may include at least one material selected from asiloxane, a thiol, a phosphate, a disulfide including a sulfur series,and an amine, and the terminal functional group 312 may include at leastone material selected from a trifluoromethyl (—CF₃), a difluorocarbene(—CF₂), a methyl (—CH₃), a methylene (—CH₂), a fluoro (—F), a hydroxylgroup (—OH), carbon (—C), and silicon (—Si). In an embodiment, the headgroup 310 may be defined by a material capable of maximizing bondingstrength with a metal, and the terminal functional group 312 may be ahydrophobic material. The head group 310 may have a large selectionratio to be specific to the metal. Therefore, the head group 310 isbonded to the metal body, and the terminal functional group 312 isdisposed in the opposite direction of the metal body, so that arepulsive force may be applied to a water-soluble material. The metalcombined with the head group 310 may be at least one metal selected fromtitanium (Ti), gold (Au), copper (Cu), nickel (Ni), silver (Ag),aluminum (Al), molybdenum (Mo), chromium (Cr), iron (Fe), ITO, IZO,tantalum (Ta), and a combination (e.g., an alloy) thereof, and thewater-soluble material acting with the repulsive force with the terminalfunctional group 312 may be a slurry. The self-assembled monolayer maybe formed by a reduction removal reaction of hydrogen after an oxidationaddition reaction for the surface of the metal.

Hereinafter, an embodiment of a manufacturing method of the displaydevice using the self-assembled monolayer will be described in detailwith reference to FIG. 4 to FIG. 8.

FIG. 4 to FIG. 8 are views showing a manufacturing method of a displaydevice according to an embodiment.

Referring to FIG. 4, in an embodiment of a manufacturing method of thedisplay device, an element part 20, an inorganic insulating layer 160,conductors 175 and 177, and an organic insulating layer 180 aresequentially provided or formed on a substrate 100.

The first conductor 175 is provided or formed in a display area DA on asubstrate 100, the inorganic insulating layer 160 is provided or formedon the first conductor 175, and the organic insulating layer 180 isprovided or formed on the inorganic insulating layer 160. The secondconductor 177 is provided or formed in the non-display area NA on thesubstrate 100, and the organic insulating layer 180 is provided orformed on the second conductor 177.

In an embodiment where the organic insulating layer 180 is formed in astate in which the composition of the organic layer is coated and cured,the upper surface may include protrusions and depressions. The organicinsulating layer 180 may be partially patterned with openings 61 and 62exposing parts of the upper surfaces of the conductors 175 and 177. Theorganic insulating layer 180 may include at least one organic materialselected from an acryl resin, an epoxy resin, a phenolic resin, apolyamide resin, and a polyimide resin, and the composition of theorganic layer may be mainly cured at the positions corresponding to theopenings 61 and 62.

Referring to FIG. 5, a sacrificial layer 300 is provided or deposited tocover the portion where the surfaces of the organic insulating layer 180and the upper surface of the conductor 175 and 177 are exposed.

The sacrificial layer 300 may be provided or formed using theself-assembled monolayer shown in FIG. 3. The sacrificial layer 300 maybe formed by a deposition process such as a thermal evaporation, aliquid coating, a chemical vapor deposition (“CVD”), a physical vapordeposition (“PVD”), or a sputtering. The sacrificial layer 300 mayprotect the conductors 175 and 177 in the process of polishing theorganic insulating layer 180.

It is desired to perform the process of polishing the protrusions anddepressions of the upper surface of the organic insulating layer 180 toprovide a flat upper surface. The upper surface of the organicinsulating layer 180 may be polished and simultaneously the sacrificiallayer 300 positioned on the upper surface of the organic insulatinglayer 180 may also be polished. The polishing process may be performedusing a chemical mechanical polishing method in which the mechanicalpolishing and the chemical polishing are performed together. A chemicalmechanical polishing is a method in which the substrate 100 is rotatedin contact with the polishing pad to be polished and simultaneously aslurry for the chemical polishing is supplied. The material contained inthe slurry is a compound that may mechanically cut the surfaces such asthe substrate 100 and the insulating layer or cut into abrasiveparticles. The slurry includes a material that chemically suppresses thepolishing of the pattern of the conductors 175 and 177 at pH 6.0 orhigher, so that the organic insulating layer 180 is polished, but theconductors 175 and 177 may have a material selection ratio at which thepolishing is suppressed. It may be desired to perform the polishingprocess using the polishing pad having a wide width overlapping thedisplay area DA and the non-display area NA to be in contact with bothdisplay area DA and non-display area NA. In this case, due to the stepof the organic insulating layer 180 of the display area DA and thenon-display area NA, the polishing pad may be in direct contact with theupper surface of the pad PAD part such that the pad PAD may be damaged.In addition, after the polishing process, the openings 61 and 62 of theorganic insulating layer 180 may not be cleaned well, so that the slurryof the upper surface of the conductors 175 and 177 may not be removed.

In an embodiment of the invention, the sacrificial layer 300 is providedor deposited on the surface of the organic insulating layer 180 and thepad PAD, such that the pad PAD may be effectively prevented from beingdamaged in the polishing process.

In such an embodiment, the slurry may be effectively removed in theopenings 61 and 62 of the organic insulating layer 180.

Referring to FIG. 6, after the polishing process is performed, thesurface of the organic insulating layer 180 is cleaned to remove theslurry and the polishing by-products, for example. The sacrificial layer300 formed on the side surface of the organic insulating layer 180 andthe upper surface of the conductor 175 and 177 is removed by the surfacetreatment.

By the polishing process, the upper surface of the organic insulatinglayer 180 has been planarized, but the slurry may remain on thesacrificial layer 300 in the openings 61 and 62 of the organicinsulating layer 180. In addition, the slurry may also remain on thesacrificial layer 300 disposed on the upper surfaces of the conductors175 and 177. The sacrificial layer 300 may be removed from the organicinsulating layer 180 and the conductor 175 and 177 by the surfacetreatment. In an embodiment, by removing the slurry remaining on thesurface of the sacrificial layer 300 along with the removal of thesacrificial layer 300, the display device may be manufactured withoutremaining the slurry in the opening of the organic insulating layer 180and the upper surfaces of the conductors 175 and 177. The surfacetreatment may use atmospheric pressure plasma or plasma discharge, andargon (Ar), oxygen (02), or nitrogen (N₂) may be used as a plasmareaction gas thereof.

Referring to FIG. 7, the head group 310 of the sacrificial layer 300 maybe disposed on the upper surface of the conductors 175 and 177 to whichthe surface treatment is completed.

In an embodiment, the bonding strength of the head group 310 and thesurfaces of the conductors 175 and 177 is greater than that of the headgroup 310 and the hydrocarbon chain 311, the head group 310 may remainon the upper surfaces of the conductors 175 and 177. In such anembodiment, the head group 310 disposed on the upper surfaces of theconductors 175 and 177 has a fineness degree of about 1 Å, all thesacrificial layer 300 may be cleaned without remaining other materialexcept for the head group 310 on the upper surfaces of the conductors175 and 177. In an embodiment, the portion of the sacrificial layer 300may remain on the upper surface of the organic insulating layer 180, butmost of the sacrificial layer 300 may be easily removed since thebonding strength of the head group 310 and the organic insulating layer180 is not greater than that of the head group 310 and the hydrocarbonchain 311.

Referring to FIG. 8, in the display area DA, a pixel electrode 191 and apartition 360 are provided or formed on the organic insulating layer180, an emission layer 370 is provided or formed on the pixel electrode191, and a common electrode 270 is provided or formed on the emissionlayer 370 and the partition 360.

Since the upper surface of the organic insulating layer 180 issubstantially flat, the thickness of the pixel electrode 191 and theemission layer 370 disposed on the organic insulating layer 180 may beeasily controlled. Accordingly, a high resolution display device may berealized, the luminance of light emitted by the light-emitting elementmay be uniform, and the pattern inside the display device may beeffectively prevented from being viewed from the outside.

Hereinafter, the display area of an embodiment of the display deviceaccording to the invention will be described with reference to FIG. 9.

FIG. 9 is a schematic cross-sectional view of a display device accordingto an embodiment. FIG. 9 is the cross-sectional view to show a stackedstructure of the display area in the display device according to anembodiment, and may schematically correspond to one pixel area.

In an embodiment, the display device includes a substrate 100,transistors 124, 130, 173, and 175 disposed on the substrate 100, and alight-emitting element LED connected to the transistors 124, 130, 173,and 175. A part of the transistor may be included in an element part 20shown in FIG. 2 to FIG. 8.

The substrate 100 may be a flexible substrate 100, and may include abarrier layer to prevent moisture, oxygen, etc. from penetrating from anoutside.

In an embodiment of the display device, a buffer layer 120 is disposedon the substrate 100. The buffer layer 120 may block the impurity thatmay be diffused from the substrate 100 to the semiconductor layer 130 inthe process of forming the semiconductor layer 130 and reduce the stressapplied to the substrate 100. The barrier layer and the buffer layer 120may include an inorganic insulating material such as a silicon oxide(SiOx), a silicon nitride (SiNx), etc.

In an embodiment of the display device, a semiconductor layer 130 of thetransistor is disposed on the buffer layer 120, and a gate insulatinglayer 140 is disposed on the semiconductor layer 130. The semiconductorlayer 130 includes a source region 132 and a drain region 133, and achannel region 131 between these regions. The semiconductor layer 130may include a polysilicon, an oxide semiconductor or an amorphoussilicon, for example.

In an embodiment of the display device, a gate conductor including agate electrode 124 of the transistor, a gate line, etc., may be disposedon the gate insulating layer 140. The gate conductor may include a metalsuch as molybdenum (Mo), copper (Cu), aluminum (Al), silver (Ag),chromium (Cr), tantalum (Ta), titanium (Ti), or a metal alloy thereof.

In an embodiment of the display device, an inorganic insulating layer160 is disposed on the gate electrode 124. The inorganic insulatinglayer 160 may be an interlayer insulating layer including an inorganicinsulating material.

In an embodiment of the display device, data conductors 173 and 175including a source electrode 173 and a drain electrode 175 of thetransistor, a data line, and a driving voltage line may be disposed onthe inorganic insulating layer 160. The source electrode 173 and thedrain electrode 175 may be respectively connected to the source region132 and the drain region 133 of the semiconductor layer 130 throughopenings in the gate insulating layer 140 and the inorganic insulatinglayer 160. The data conductors 173 and 175 may include a metal, such asaluminum (Al), copper (Cu), silver (Ag), molybdenum (Mo), chromium (Cr),gold (Au), platinum (Pt), palladium (Pd), tantalum (Ta), tungsten (W),titanium (Ti), nickel (Ni), ITO and IZO, or a metal alloy thereof.

In an embodiment of the display device, an organic insulating layer 180may be disposed on the inorganic insulating layer 160 and the dataconductors 173 and 175. The organic insulating layer 180 may have a flatsurface on which the light-emitting element LED is to be disposed toincrease the light emission efficiency of the light-emitting element LEDdisposed thereon.

In an embodiment of the display device, the light-emitting element LEDincluding the pixel electrode 191, the emission layer 370, and thecommon electrode 270 disposed on the light-emitting element LED isdisposed on the organic insulating layer 180.

In an embodiment of the display device, an encapsulation layer 400 maybe disposed on the light-emitting element LED. The encapsulation layer400 encapsulates the light-emitting element LED to prevent moisture oroxygen from penetrating from the outside. The encapsulation layer 400may include at least one inorganic material layer and at least oneorganic material layer, and the inorganic material layer and the organicmaterial layer may be alternately stacked.

The invention should not be construed as being limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete and will fully conveythe concept of the invention to those skilled in the art.

While the invention has been particularly shown and described withreference to embodiments thereof, it will be understood by those ofordinary skill in the art that various changes in form and details maybe made therein without departing from the spirit or scope of theinvention as defined by the following claims.

What is claimed is:
 1. A manufacturing method of a display device, themanufacturing method comprising: providing a conductor on a substrate;providing an organic insulating layer on the conductor and forming anopening through the organic insulating layer to expose a part of anupper surface of the conductor; depositing a sacrificial layer to covera surface of the organic insulating layer and the part of the uppersurface of the conductor exposed through the opening; polishing an uppersurface of the organic insulating layer; and surface-treating thesacrificial layer on a side surface of the organic insulating layer andthe upper surface of the conductor, wherein the sacrificial layerincludes a self-assembled monolayer.
 2. The manufacturing method ofclaim 1, wherein the self-assembled monolayer includes a head group, ahydrocarbon chain and a terminal functional group, and the head groupincludes at least one selected from a siloxane, a thiol, and aphosphate.
 3. The manufacturing method of claim 2, wherein the terminalfunctional group includes at least one selected from a trifluoromethyl(—CF₃), a difluorocarbene (—CF₂), a methyl (—CH₃), a methylene (—CH₂), afluoro (—F), a hydroxyl group (—OH), carbon (—C), and silicon (—Si). 4.The manufacturing method of claim 2, wherein the sacrificial layer isdeposited by a thermal evaporation, a liquid coating, a chemical vapordeposition, a physical vapor deposition, or a sputtering.
 5. Themanufacturing method of claim 2, wherein the upper surface of theorganic insulating layer covered by the sacrificial layer includesprotrusions and depressions.
 6. The manufacturing method of claim 2,wherein the head group is disposed on the upper surface of the conductoron which a surface treatment is completed.
 7. The manufacturing methodof claim 1, wherein the conductor includes at least one materialselected from titanium (Ti), iron (Fe), nickel (Ni), copper (Cu),molybdenum (Mo), indium tin oxide, and indium zinc oxide.
 8. Themanufacturing method of claim 1, wherein the organic insulating layerincludes at least one organic material selected from acryl resin, epoxyresin, phenolic resin, polyamide resin, and polyimide resin.
 9. Themanufacturing method of claim 1, wherein, the polishing the uppersurface of the organic insulating layer includes using a chemicalmechanical polishing method.
 10. The manufacturing method of claim 9,wherein the chemical mechanical polishing method is performed bycontacting a polishing pad to the upper surface of the organicinsulating layer and supplying a slurry.
 11. The manufacturing method ofclaim 10, wherein the substrate includes a display area and anon-display area surrounding the display area, the conductor includes afirst conductor provided in the display area, and a second conductorprovided in the non-display area.
 12. The manufacturing method of claim11, wherein the polishing pad overlaps the display area and thenon-display area when the polishing pad contacts the upper surface ofthe organic insulating layer for the chemical mechanical polishingmethod.
 13. The manufacturing method of claim 12, further comprising:providing a pixel electrode, an emission layer, and a common electrodeon the organic insulating layer in the display area, wherein theself-assembled monolayer includes a head group, a hydrocarbon chain anda terminal functional group, the head group includes at least oneselected from a siloxane, a thiol, and a phosphate, and the head groupis disposed between the pixel electrode and the first conductor.